1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * linux/include/linux/sunrpc/sched.h
4  *
5  * Scheduling primitives for kernel Sun RPC.
6  *
7  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
8  */
9 
10 #ifndef _LINUX_SUNRPC_SCHED_H_
11 #define _LINUX_SUNRPC_SCHED_H_
12 
13 #include <linux/timer.h>
14 #include <linux/ktime.h>
15 #include <linux/sunrpc/types.h>
16 #include <linux/spinlock.h>
17 #include <linux/wait_bit.h>
18 #include <linux/workqueue.h>
19 #include <linux/sunrpc/xdr.h>
20 
21 /*
22  * This is the actual RPC procedure call info.
23  */
24 struct rpc_procinfo;
25 struct rpc_message {
26 	const struct rpc_procinfo *rpc_proc;	/* Procedure information */
27 	void *			rpc_argp;	/* Arguments */
28 	void *			rpc_resp;	/* Result */
29 	const struct cred *	rpc_cred;	/* Credentials */
30 };
31 
32 struct rpc_call_ops;
33 struct rpc_wait_queue;
34 struct rpc_wait {
35 	struct list_head	list;		/* wait queue links */
36 	struct list_head	links;		/* Links to related tasks */
37 	struct list_head	timer_list;	/* Timer list */
38 };
39 
40 /*
41  * This is the RPC task struct
42  */
43 struct rpc_task {
44 	atomic_t		tk_count;	/* Reference count */
45 	int			tk_status;	/* result of last operation */
46 	struct list_head	tk_task;	/* global list of tasks */
47 
48 	/*
49 	 * callback	to be executed after waking up
50 	 * action	next procedure for async tasks
51 	 */
52 	void			(*tk_callback)(struct rpc_task *);
53 	void			(*tk_action)(struct rpc_task *);
54 
55 	unsigned long		tk_timeout;	/* timeout for rpc_sleep() */
56 	unsigned long		tk_runstate;	/* Task run status */
57 
58 	struct rpc_wait_queue 	*tk_waitqueue;	/* RPC wait queue we're on */
59 	union {
60 		struct work_struct	tk_work;	/* Async task work queue */
61 		struct rpc_wait		tk_wait;	/* RPC wait */
62 	} u;
63 
64 	/*
65 	 * RPC call state
66 	 */
67 	struct rpc_message	tk_msg;		/* RPC call info */
68 	void *			tk_calldata;	/* Caller private data */
69 	const struct rpc_call_ops *tk_ops;	/* Caller callbacks */
70 
71 	struct rpc_clnt *	tk_client;	/* RPC client */
72 	struct rpc_xprt *	tk_xprt;	/* Transport */
73 	struct rpc_cred *	tk_op_cred;	/* cred being operated on */
74 
75 	struct rpc_rqst *	tk_rqstp;	/* RPC request */
76 
77 	struct workqueue_struct	*tk_workqueue;	/* Normally rpciod, but could
78 						 * be any workqueue
79 						 */
80 	ktime_t			tk_start;	/* RPC task init timestamp */
81 
82 	pid_t			tk_owner;	/* Process id for batching tasks */
83 
84 	int			tk_rpc_status;	/* Result of last RPC operation */
85 	unsigned short		tk_flags;	/* misc flags */
86 	unsigned short		tk_timeouts;	/* maj timeouts */
87 
88 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
89 	unsigned short		tk_pid;		/* debugging aid */
90 #endif
91 	unsigned char		tk_priority : 2,/* Task priority */
92 				tk_garb_retry : 2,
93 				tk_cred_retry : 2,
94 				tk_rebind_retry : 2;
95 };
96 
97 typedef void			(*rpc_action)(struct rpc_task *);
98 
99 struct rpc_call_ops {
100 	void (*rpc_call_prepare)(struct rpc_task *, void *);
101 	void (*rpc_call_done)(struct rpc_task *, void *);
102 	void (*rpc_count_stats)(struct rpc_task *, void *);
103 	void (*rpc_release)(void *);
104 };
105 
106 struct rpc_task_setup {
107 	struct rpc_task *task;
108 	struct rpc_clnt *rpc_client;
109 	struct rpc_xprt *rpc_xprt;
110 	struct rpc_cred *rpc_op_cred;	/* credential being operated on */
111 	const struct rpc_message *rpc_message;
112 	const struct rpc_call_ops *callback_ops;
113 	void *callback_data;
114 	struct workqueue_struct *workqueue;
115 	unsigned short flags;
116 	signed char priority;
117 };
118 
119 /*
120  * RPC task flags
121  */
122 #define RPC_TASK_ASYNC		0x0001		/* is an async task */
123 #define RPC_TASK_SWAPPER	0x0002		/* is swapping in/out */
124 #define RPC_TASK_MOVEABLE	0x0004		/* nfs4.1+ rpc tasks */
125 #define RPC_TASK_NULLCREDS	0x0010		/* Use AUTH_NULL credential */
126 #define RPC_CALL_MAJORSEEN	0x0020		/* major timeout seen */
127 #define RPC_TASK_DYNAMIC	0x0080		/* task was kmalloc'ed */
128 #define	RPC_TASK_NO_ROUND_ROBIN	0x0100		/* send requests on "main" xprt */
129 #define RPC_TASK_SOFT		0x0200		/* Use soft timeouts */
130 #define RPC_TASK_SOFTCONN	0x0400		/* Fail if can't connect */
131 #define RPC_TASK_SENT		0x0800		/* message was sent */
132 #define RPC_TASK_TIMEOUT	0x1000		/* fail with ETIMEDOUT on timeout */
133 #define RPC_TASK_NOCONNECT	0x2000		/* return ENOTCONN if not connected */
134 #define RPC_TASK_NO_RETRANS_TIMEOUT	0x4000		/* wait forever for a reply */
135 #define RPC_TASK_CRED_NOREF	0x8000		/* No refcount on the credential */
136 
137 #define RPC_IS_ASYNC(t)		((t)->tk_flags & RPC_TASK_ASYNC)
138 #define RPC_IS_SWAPPER(t)	((t)->tk_flags & RPC_TASK_SWAPPER)
139 #define RPC_IS_SOFT(t)		((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT))
140 #define RPC_IS_SOFTCONN(t)	((t)->tk_flags & RPC_TASK_SOFTCONN)
141 #define RPC_WAS_SENT(t)		((t)->tk_flags & RPC_TASK_SENT)
142 #define RPC_IS_MOVEABLE(t)	((t)->tk_flags & RPC_TASK_MOVEABLE)
143 
144 #define RPC_TASK_RUNNING	0
145 #define RPC_TASK_QUEUED		1
146 #define RPC_TASK_ACTIVE		2
147 #define RPC_TASK_NEED_XMIT	3
148 #define RPC_TASK_NEED_RECV	4
149 #define RPC_TASK_MSG_PIN_WAIT	5
150 #define RPC_TASK_SIGNALLED	6
151 
152 #define rpc_test_and_set_running(t) \
153 				test_and_set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
154 #define rpc_clear_running(t)	clear_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
155 
156 #define RPC_IS_QUEUED(t)	test_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
157 #define rpc_set_queued(t)	set_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
158 #define rpc_clear_queued(t)	clear_bit(RPC_TASK_QUEUED, &(t)->tk_runstate)
159 
160 #define RPC_IS_ACTIVATED(t)	test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate)
161 
162 #define RPC_SIGNALLED(t)	test_bit(RPC_TASK_SIGNALLED, &(t)->tk_runstate)
163 
164 /*
165  * Task priorities.
166  * Note: if you change these, you must also change
167  * the task initialization definitions below.
168  */
169 #define RPC_PRIORITY_LOW	(-1)
170 #define RPC_PRIORITY_NORMAL	(0)
171 #define RPC_PRIORITY_HIGH	(1)
172 #define RPC_PRIORITY_PRIVILEGED	(2)
173 #define RPC_NR_PRIORITY		(1 + RPC_PRIORITY_PRIVILEGED - RPC_PRIORITY_LOW)
174 
175 struct rpc_timer {
176 	struct list_head list;
177 	unsigned long expires;
178 	struct delayed_work dwork;
179 };
180 
181 /*
182  * RPC synchronization objects
183  */
184 struct rpc_wait_queue {
185 	spinlock_t		lock;
186 	struct list_head	tasks[RPC_NR_PRIORITY];	/* task queue for each priority level */
187 	unsigned char		maxpriority;		/* maximum priority (0 if queue is not a priority queue) */
188 	unsigned char		priority;		/* current priority */
189 	unsigned char		nr;			/* # tasks remaining for cookie */
190 	unsigned short		qlen;			/* total # tasks waiting in queue */
191 	struct rpc_timer	timer_list;
192 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
193 	const char *		name;
194 #endif
195 };
196 
197 /*
198  * This is the # requests to send consecutively
199  * from a single cookie.  The aim is to improve
200  * performance of NFS operations such as read/write.
201  */
202 #define RPC_IS_PRIORITY(q)		((q)->maxpriority > 0)
203 
204 /*
205  * Function prototypes
206  */
207 struct rpc_task *rpc_new_task(const struct rpc_task_setup *);
208 struct rpc_task *rpc_run_task(const struct rpc_task_setup *);
209 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req);
210 void		rpc_put_task(struct rpc_task *);
211 void		rpc_put_task_async(struct rpc_task *);
212 bool		rpc_task_set_rpc_status(struct rpc_task *task, int rpc_status);
213 void		rpc_task_try_cancel(struct rpc_task *task, int error);
214 void		rpc_signal_task(struct rpc_task *);
215 void		rpc_exit_task(struct rpc_task *);
216 void		rpc_exit(struct rpc_task *, int);
217 void		rpc_release_calldata(const struct rpc_call_ops *, void *);
218 void		rpc_killall_tasks(struct rpc_clnt *);
219 unsigned long	rpc_cancel_tasks(struct rpc_clnt *clnt, int error,
220 				 bool (*fnmatch)(const struct rpc_task *,
221 						 const void *),
222 				 const void *data);
223 void		rpc_execute(struct rpc_task *);
224 void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
225 void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
226 void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
227 unsigned long	rpc_task_timeout(const struct rpc_task *task);
228 void		rpc_sleep_on_timeout(struct rpc_wait_queue *queue,
229 					struct rpc_task *task,
230 					rpc_action action,
231 					unsigned long timeout);
232 void		rpc_sleep_on(struct rpc_wait_queue *, struct rpc_task *,
233 					rpc_action action);
234 void		rpc_sleep_on_priority_timeout(struct rpc_wait_queue *queue,
235 					struct rpc_task *task,
236 					unsigned long timeout,
237 					int priority);
238 void		rpc_sleep_on_priority(struct rpc_wait_queue *,
239 					struct rpc_task *,
240 					int priority);
241 void		rpc_wake_up_queued_task(struct rpc_wait_queue *,
242 					struct rpc_task *);
243 void		rpc_wake_up_queued_task_set_status(struct rpc_wait_queue *,
244 						   struct rpc_task *,
245 						   int);
246 void		rpc_wake_up(struct rpc_wait_queue *);
247 struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *);
248 struct rpc_task *rpc_wake_up_first_on_wq(struct workqueue_struct *wq,
249 					struct rpc_wait_queue *,
250 					bool (*)(struct rpc_task *, void *),
251 					void *);
252 struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
253 					bool (*)(struct rpc_task *, void *),
254 					void *);
255 void		rpc_wake_up_status(struct rpc_wait_queue *, int);
256 void		rpc_delay(struct rpc_task *, unsigned long);
257 int		rpc_malloc(struct rpc_task *);
258 void		rpc_free(struct rpc_task *);
259 int		rpciod_up(void);
260 void		rpciod_down(void);
261 int		rpc_wait_for_completion_task(struct rpc_task *task);
262 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
263 struct net;
264 void		rpc_show_tasks(struct net *);
265 #endif
266 int		rpc_init_mempool(void);
267 void		rpc_destroy_mempool(void);
268 extern struct workqueue_struct *rpciod_workqueue;
269 extern struct workqueue_struct *xprtiod_workqueue;
270 void		rpc_prepare_task(struct rpc_task *task);
271 gfp_t		rpc_task_gfp_mask(void);
272 
273 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS)
rpc_qname(const struct rpc_wait_queue * q)274 static inline const char * rpc_qname(const struct rpc_wait_queue *q)
275 {
276 	return ((q && q->name) ? q->name : "unknown");
277 }
278 
rpc_assign_waitqueue_name(struct rpc_wait_queue * q,const char * name)279 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
280 		const char *name)
281 {
282 	q->name = name;
283 }
284 #else
rpc_assign_waitqueue_name(struct rpc_wait_queue * q,const char * name)285 static inline void rpc_assign_waitqueue_name(struct rpc_wait_queue *q,
286 		const char *name)
287 {
288 }
289 #endif
290 
291 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
292 int rpc_clnt_swap_activate(struct rpc_clnt *clnt);
293 void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt);
294 #else
295 static inline int
rpc_clnt_swap_activate(struct rpc_clnt * clnt)296 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
297 {
298 	return -EINVAL;
299 }
300 
301 static inline void
rpc_clnt_swap_deactivate(struct rpc_clnt * clnt)302 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
303 {
304 }
305 #endif /* CONFIG_SUNRPC_SWAP */
306 
307 #endif /* _LINUX_SUNRPC_SCHED_H_ */
308